Hypoglycemia is the most common adverse effect of diabetes treatment. Severe hypoglycemia is more frequent in older adults than their younger counterparts and is associated with increased risk of falls, fractures, dementia, cardiovascular events, mortality, and poor quality of life. Diabetes care quality metrics focus almost exclusively on prevention of hyperglycemia and its complications and reward target-based glucose lowering - this can potentially lead to one-size-fits-all clinical practice and an increase in adverse event. Recent clinical guidelines call for individualized goal-setting in diabetes care, but data on how t personalize care to maximize benefits and minimize adverse events are lacking. A clear and comprehensive understanding of the burden of hypoglycemia on patients and a rigorous examination of risk factors for hypoglycemia are required to inform treatment decisions in older persons with diabetes, assess an important aspect of current quality of care, and provide future targets for intervention that may mitigate the burden of hypoglycemia. The candidate's career goal is to become an independent clinical investigator in the field of diabetes and geriatrics, generating knowledge to help guide personalized diabetes treatment. In this proposal, the candidate will apply rigorous epidemiologic, biostatistical, and qualitative research methods to evaluate older patients who experience severe hypoglycemia, identify potential contributors to hypoglycemia admissions, and examine the relationship between specific glucose targets, glucose-lowering therapies and hypoglycemic events in order to provide better information on treatment-related adverse events and improve clinical outcomes. Specific Aim 1: To characterize recent trends in hospital admissions for hypoglycemia among older Medicare recipients with diabetes for a 12-year period from 1998-2010, and to examine race, gender, and geographic differences in these trends. Specific Aim 2: To elucidate factors that may contribute to the risk of hospitalization for hypoglycemia among a sample of older adults with diabetes using qualitative methods. Specific Aim 3: To evaluate the association between glycemic control, glucose-lowering agents, and hypoglycemic events in the Diabetes Study of Northern California (DISTANCE), a multiethnic cohort of 20,000 patients with diabetes in a large integrated healthcare delivery system. The combination of a large scale surveillance approach, primary data collection to investigate potential reasons for hypoglycemia hospital admissions, and a detailed analysis of a clinical registry will provide the candidate with additional skills in large database analyses, qualitative research methods, and epidemiologic aging research - and will lead to future work to comprehensively understand the balance of risks and benefits of glucose-lowering therapy in older adults.